Steel blade with no sharp edges to swiftly saw cardboard. Here's a tip that may be handy when using the Makedo SAFE-SAW: Punch a row of holes along the line of your cut, about 1" apart... then use the saw to "join the dots". This works well for straight and curved cuts, as well as cutouts such as holes, windows or doors. The punch on the end of the saw can also be used to score the cardboard, to create folds and more sculptural forms. For more advanced cardboard construction, try the Makedo Fold-roller. SAFETY: Makedo is designed to meet and exceed international safety requirements for toys. This product has been independently tested to an age grading of 3+ and complies to the following international standards: - ASTM F963 - Canada Toys Regulations SOR - EU REACH / EN71 - AS/NZS 8124 MD-30004